Electron tube socket with replaceable by-pass capacitors



Jan. 26, 1954 s o F 2,667,573

ELECTRON TUBE SOCKET WITH REPLACEABLE BY-PASS CAPACITORS Filed June 15,1952 INVEN TOR.

54 1 0 fiflf/AWFF Patented Jan. 26, 1954 ELECTRON TUBE SOCKET WITHREPLACE- ABLE BY-PASS CAPACITORS David Satinoff, Utica, N. Y., assignorto the United States of America as represented by the Scoretary of theAir Force Application June 13, 1952, Serial No. 293,490 2 Claims. (01.25016.4)

(Granted under Title 35, U. S. Code (1952),

see. 266

The invention described in the following specification and claims may bemanufactured and used by or for the Government for governmentalpurposes, without the payment to me of any royalty thereon.

This invention relates to electron tube sockets, particularly thoseintended for use in high-frequency circuits. It is the object of theinvention to provide an electron tube socket having bypass condenserslocated in the socket body so as to provide minimum lead lengths betweenthe tube electrodes and the condensers. It is another object of theinvention to provide a socket of the above type in which the condensersare easily removed and replaced from the bottom of the socket withoutthe use of tools and with minimum disturbance to the wiring attached tothe socket. It is a further object of the invention to provide a socketof the above type in which the top is identical to that of aconventional socket with conventional pin hole sizes. This isparticularly important in the case of miniature tubes having smallclosely spaced prongs which are easily bent or misaligned.

A more detailed description of the socket will be given in connectionwith the accompanying drawings, in which Fig. l is a completelyassembled socket in accordance with the invention;

Fig. 2 is a top view of the socket;

Fig. 3 is a view of the bottom or wiring side of the socket;

Fig. 4 is a sectional view of the socket;

Fig. 5 shows the construction of the by-pass condensers and the socketcontacts; and

Fig. 6 shows the condenser and contact retaining device.

The socket illustrated in the drawings is for a standard seven pinminiature tube, however. the design is of course not limited to thistype which is shown by way of example only. Referring to Fig. l thesocket has a body I of a suitable insulating material. A metallic saddle2 is attached to the body I for mounting the socket on a chassis 3 bymeans of screws or brads 4. The various contacts of the socket, whichcontact the pins of tube 5, terminate in lugs E to which the necessarywiring may be attached for connecting the tube into a circuit. Elements1 are metallic grounding strips leading to saddle 2 the purpose of whichwill be explained later.

The top or the socket is conventional as shown in Fig. 2. The holes 8are only slightly larger than the base pins or the tube and serve duringinsertion of the tube to align the pins with respect to the contactswithin the socket. As shown in Fig. 4, beneath each of the pin holes 8and concentric therewith there is located in the body of the socket acylindrical recess 9 of greater diameter than the pin holes. A springcontact finger I0 is located in each of the re-. cesses and is connectedto saddle 2 by a ground. ing strip 1. The contact finger is preferablymade of a springy metal and is biased away from the wall of the recess.

The designs of the by-pass condensers and the socket contacts are shownin Fig. 5. The condensers are of the concentric type each consisting ofa sleeve I I of ceramic or other suitable insulating material havinginner and outer coat.- ings l2 and 13 of metal such .as silver to formtwo plates of a condenser. The socket contact has a cylindrical bodyportion it part of the lower end of which is extended in fiat form toprovide a soldering lug 6. .The upper part of the body I 4 is crimpedinwardly near the end and slightly flared outwardly at the end toreceive the base pin of the tube and to make good contact therewith. Thelower end of body portion 14 is shaped to form a pair of contact fingersl5 for making contact with the inner coating i2 01 the by-pass condenserwhen the contact is in its normal position inside the condenser.

When the con-denser with contact inserted there-. in is placed in recess9 of the socket, a shownin Fig. 4, contact finger It connects the outermetallic coating l3 to ground thus forming a capacitive by-pass betweenthe socket contact and ground. By-pass condensers of the type-- shown inFig. 5 are placed wherever required in the socket. For those electrodesthat do not require by-passing, dummy sleeves are used which may simplybe sleeves ll without the metallic coatings.

The by-pass condensers, or dummy sleeves, and the socket contacts arelocked in place in the socket by means of a retaining device shown inFigs. 4 and 6. This device consists of a hollow metallic pin having ashank l5 and a head ll of larger diameter than the shank. A retainingdisc I8 is rotatably fitted to the shank of the pin and urged toward thehead by spring Ill. The end of the shank is formed into two outwardlyextending diametrically opposite ears or bayonets 26. Spring 19 isretained on the shank by these ears and by collar 2! which is slidableon the shank.

The body of the socket is provided with a central cylindrical passageway22 having two diametrically opposite longitudinal slots 23. These arebest seen in Fig. 3, which is a bottom view of the socket with theretaining device removed. The size of the passageway and slots is suchas to permit passage of the shank "5 together with ears 20 and spring l9readily therethrough. The

3 upper end of passageway 22 is counterbored to receive a metallicinsert 24. The insert also has a cylindrical passageway therethroughwhich however" is large enough to permit passage of shank [6 but notlarge enough to permit passage of collar 2!. The slots 23 on the otherhand continue through the insert undiminished in size, as shown in Fig.3. The end of insert 24 is notched sufiiciently to permit cars 20 to berotated 90 when the pin is fully inserted in the socket with theretaining ring IS in contact with the bottom of the socket. This actionlocks the retaining device in the socket. The pressure developed betweenears 20 and insert 24 due to spring 19 causes the retaining device to befrictionally held in its locked position against vibration or accidentalmovement. The retainer may be easily unlocked andremoved by rotating thehead I! ninety degrees counterclockwise, as seen from the bottom, whichbrings ears 20 into alignment with grooves, 24 and permits withdrawal ofthe pin; The diameter of disc I8 is made large enough to substantiallycover the ends of the condenser sleeves, or dummy sleeves, therebyretaining the sleeves and the socket contacts in the socket. Thecontacts are positioned in the sockets with theirlugs toward theoutside, as shown inFig. 3, and the retaining disc is provided withnotches deep enough to permit passage of lugs 6 without uncovering theends of the contact bodies l4. Asan aid in rotating the pin of theretaining device the. head I! may be castellated as shown in thedrawing.

The pin alt-I?! also serves as a central shield between the. contacts.of the socketiand between the lugs 6:; Inorderto ground the pin forthis purpose a-Wire 26, lying in a groove in the face of the socket,isused to connect the metallic insert- 24 to the saddlerZ.

I claim .1. An electron tube socket comprising a'body of insulating.material, a plurality of holes in the topof said body corresponding insize and position'to the base pins of an electron tube, each of saidholes opening into a cylindrical recess coaxialv therewith and extendingthrough the bottom of said body, .a-removablesleeve of insulatingmaterial in each of said recesses, a contact element in each ofsaidsleeves, said contact element having means to contact the base pinof anelectron tube and also having means to contact the inner surfaces ofsaid sleeves, the outer ends of said sleeves and contact elements beingflush with the bottom of said socket body, an electrical round contactin each of said recesses and in contact with the outer surfaces of saidsleeves, at least one of said sleeves having its inner and outersurfaces coated with metallic films to form a condenser, and means forretaining said sleeves and said contact elements in said socket body,said means comprising a retaining plate of insulating material, ametallic pin having a shank portion and a head portion, said plate beingrotatably mounted on said shank next to said head portion, said shankportion having its end terminated in a pair of diametrically oppositeoutwardly extending cars, a coil spring in compression positioned aroundsaid shank betweenv said ears and said head portion, a centrally locatedpassageway through said socket slightly larger than said spring andhaving oppositely disposed longitudinal grooves to permit passage ofsaid ears, .a metallic insert in the top end of said passageway, apassageway through said insert large enough to permit passage of saidshank portion but small enough to prevent passage of said spring, saidinsert having the grooves of said body passageway continued therethroughand notched sidewise at a point in said insert to permit rotation ofsaid ears through approximately ninety degrees, whereby said pin may belocked in said socket body and thereby fasten said plate to the bottomof said socket body, the size and shape of said plate being such as tooverlap at least a portion of the exposed ends of said sleeves and saidcontact elements.

2. Apparatus as claimed in claim 1 in which means are provided forgrounding said metallic insert.

DAVID SATINOFF.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,343,675 Kenyon Mar. 7, 1944 2,421,780 Frear June 10, 19472,571,845 Del Camp Oct. 16, 1951 2,625,582 Heibel Jan. 13, 1953

